Thank you for your quick response. Thanks to your hints the problem is solved. The problem was caused by the checkbox "Overwrite existing pages" in the security tab. It seems that checking this option overwrites all authentication windows when saving the application settings, even if the settings are not related to authentication. In this case it was the internationalization settings in the "settings" tab.
I have another question about internationalization: Once the cultures have been implemented, we get the files xxx.yyy.resx where we have to translate the strings. Among other things, we can translate the column names of the DataGrids. However, no string in the corresponding xxx.yyy.resx file seems to be provided for translating the texts of the filter window.
I know that the text in the filter window can be modified using the fields in the DataGrids properties window, but it seems essential to me that these fields can be translated automatically depending on the culture selected.
So my question is this: Is there any way, either in Radzen or in Visual Studio to translate the texts of these filter windows? I have looked through the file tree of our project's solution and I can't find any .razor file where the standard translation mechanism of Blazor could be implemented.
Thanks in advance for your help